Railway signaling.



H. W. GRIFFIN- RAlLWAY SIGNALING. APPLICATION men mull. 1913.

1.21 1 ,140. Patented Jan. 2, 1917.

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H. W. GRIFFIN.

RAILWAY SIGNALING. APPLICATIONIHLED JAN. 27. 1913.

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H. W. GRIFFIN.

RAILWAY SIGNALING. APPLICATION FILED JAN. 27. ms.

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1,21 1,140. Patented Jan. 2, 1917.

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L EL A N m EL 0 t5 E N Q N ||i} O v 3 m Mg 1 K D N \1 m Q: s 21' Qwrmzsszs N INVENTOR ETNFEEE STATES FATENT @FFEQE HENRY W. GRIFFIN, OFNEW YORK, N. Y., ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OFSWISSVALE, PENNSYLVANIA, A CORPOBATIGN OF PENNSYLVANIA.

RAILWAY SIGNALING.

Application filed January 27, 1913.

To all whom it may concern:

is it known that I, HENRY W. GRIFFIN, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Railway Signaling,of which the following is a specification.

My invention relates to railway signaling and is particularly adaptedfor signaling on stretches of single track over which traffic moves inboth directions.

I will describe several forms of railway signaling embodying myinvention and will then point out the novel features thereof in claims.

In the accompanying drawings, Figure 1 is a diagrammatic view showing astretch of track having applied thereto one arrangement of apparatus andcircuits embodying my invention. Figs. 2, 3, 4t and 5 are views similarto Fig. 1 but showing modifications of the apparatus and circuits shownin Fig. 1.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Fig. 1, A designates the tracl; rails of a stretch ofrailway track over which traffic moves in both directions. he trackrails of the stretch A. are electrically separated from the adjoiningtrack rails by insulations 27. The stretch A is provided with a trackcircuit comprising the track rails, a source of current connected withthe track rails adjacent the middle point of the stretch and two trackrelays it and R connected with the track rails adjacent the ends of thestretch. As here shown the source of current is a transformer T whosesecondary is connected with the track rails and whose primary isconnected with a suitable source of alternating signaling current, notshown. Inasmuch as the signaling current is alternating, the trackrelays, R, R are preferably of a type responsive only to alternatingcurrent; as here shown, they are of the vane type.

With a track circuit arranged as just described, it is well known thatwhen a car or train enters the track circuit from either Specificationof Letters Patent.

Patented Jan. 2, 1917.

Serial No. 744,367.

end, it first opens the relay adjacent that end but the relay adjacentthe other end is not opened until the car or train reaches a point nearthe point of connection of the source of current with the track rails;after the car or train has passed a short distance beyond the point ofconnection of the source of current with the track rails, the relayfirst opened again closes, but the other relay, of course, remains openuntil the car or train leaves the track circuit.

Trafiic into the stretch A is governed by two end signals S and S,located respec tively adjacent the ends of the stretch. I also provideintermediate signals 13 and B; signal B is located in advance of signalS but in the rear of the shunting point of track relay it, and similarlysignal B is located in advance of signal S but in the rear of theshunting point of track relay It; as here shown, the distance of eachintermediate signal B, B from the adjacent end of the stretch is aboutone quarter of the distance from the end of the stretch to the middle,although I do not wish to limit myself to this particular location ofthese signals. T.

itach of the four slgnals is adapted to indicate stop and proceed; ashere shown, all four of the signals are of the semaphore type, but it isunderstood that other types of signal may equally well be employed. Thetwo signals S and B adjacent one end of the stretch are controlled bythe track relay It at the other end of the stretch, and the end signal Sis also controlled by the adjacent track relay B. As shown in Fig. 1,this control of the signals S and B is accomplished as follows: Signal13 is provided with control circuit comprising source of current 11,armature contact 12 of relay R, wire 13, signal B, wire 14, common wire0 to the source 11. Operatively connected with the signal B is a circuitcontroller 10 arranged to be closed or open according as the signal Bindicates proceed or stop. Signal S is provided with a control circuitas follows: From source of current 21 through wire 22, circuitcontroller 10, wire 23, armature contact 24 of relay R, wire 25, signalS, wire 26, common wire 0 to source of current 21. Hence, it will beseen that signal B is controlled by track relay R, and that signal S iscontrolled by track relay B- and by circuit controller 10 operated bysignal B,

traced. V I

The operation of the system shown in Fig. 1 is as follows: Assume that acar or train passes through the stretch A from west to east. As this caror train enters the stretch, it'opens track relay R, thereby causingsignals S, B and S to indicate stop. The opening of relay B- does not,however, affect signal B, and this latter signal continues to indicateproceed until after it has been passed by the car or train. When the caror train reaches the shunting point of track relay B, this relay opens,thereby causing signal B to indicate stop. As the car or train proceedsstill farther through the stretch it reaches a point where relay Bcloses, and signal B then changes to proceed indication. lay R, however,remains open, hence signals S, B and S continue to indicate stop untilthe car or train passes out of the stretch. The operation of theapparatus for the "passage of a car or trainthrough the stretch fromeast to west is similar to that just explained. If two cars or trainsmoving in opposite directions should enter the stretch A at the sametime, it is obvious that neither car or train would receive a stopindication at signals S and S, hence for several reasons, viz., first,so that the distance between each end signal and the adjacentintermediate signal can be made uniform for both long and shortblocks;'second, so that a car or train will not be required to back uptoo far in case it finds theintermediate signal indicating stop; third,so that when a car or train approaches an intermediate signal the driverwill not be under the impression that he is'approaching a new blocksection.

Referring now to Fig. 2, the modification 1 7 here shown is similar tothat shown in Fig.

1 except that instead of controlling'signal Both signals 'B' and Bwould,

S by a circuit controller'operated by signal B, the circuit for signal Sis a branch of the circuit for signal B. The circuit for signal B isfrom source. of current 11 through armature contact 12, wires 13 and 15,signal B, wire 16, common wire 0 to source 11. The circuit for signal Sis the same as that just traced for signal B up to and including wire13, then through wire 17, armature contact 18 of relay B, wire 19,signal S, wire 20, common wire 0 to source 11. The control of; signals Sand B is similar to the control of signals S and B. The operation of thesystem shown in Fig. 2 is substantially the same as that shown in Fig.1, hence, it need not be explained in detail. 7

Referring now to Fig. 3, the apparatus and circuits here shown aresimilar to the apparatus and circuits shown in the preceding viewsexcept the intermediate sig nals are of the light type instead of thesemaphore type, as shown in the preceding views. I have here designatedthese intermediate signals as G, C. Each signal G, C comprises twoelectric lamps r and g. The lamps are provided with lenses or glasses ofdifferent colors; for example, lamp 1* may be provided with a red lensor glass, and lamp g'may be provided with green lens or glass. It isunderstood that, as usual, when the red lamp is illuminated the signalindicates stop, and when the green lamp is illuminated the signal indi-,

cates proceed. Each signal C, C is controlled by a signal relayDor D,and the control of each of these signals is such that when thecorresponding relay is energized the green lamp 9 is illuminated andwhen the correspondlng signal relay 1s deenergiZed the red lamp 1? isilluminated. For example, the circuit for the green lamp 9 of signal Cis from thesourcexof current 28,

through armature contact 29 of relay D, wlre 30, lamp 9, w1re18l, commonwire O to source 28. It will be seen that this circuit is closed onlywhen relay D, is energized, The circuit for red lamp 7 of signal C isfrom source 28 through armature con-f tact 29, wire 32, red lamp-r wire31, common wire 0 to source 28. 'It will be seen that this circuit isclosed only when the relay D is deenergized. The circuits for signal 0are similar tothose just traced for. signal 0. Signal S and signal relayD are each controlled by relay R, and signal S is also controlled byrelay B. As'here shown, this control is the same as the control ofsignals S and B n the arrangement shown in Fig. 2, that 1s, signal Sandrelay V D are included in multiple branches of the same circuit.Similarly signal S and signal relay D are each controlled by track relayR and signal S is also controlled'byt'raclr relay R. r r 1 r Theoperation of the system shown in Fig. 3 will be evident from theexplanation given hereinbefore as to the preceding views.

Referring now to Fig. 4, the arrangement of track circuit and signals isthe same as that shown in Fig. 3. In Fig. 4, however signals C, C arecontrolled respectively by polarized relays E and E. The circuit for redlamp 0" of signal C is from source of current 28 through wires 33 and34, contact 35 of polarized armature, wire 36, lamp 1', wire 37 tosource 28. It will be seen that this circuit is closed only when therelay E is energized in such direction as to close contact 35. Thiscircuit is provided with a branch around polarized armature contact 35,which branch comprises wire 42, contact 43 of neutral armature, and wire44; hence, it will be seen that the red lamp 1 is always illuminatedwhen the relay E is deenergized. The circuit for green lamp 9 is fromsource 28 through wire 33, contact 38 of polarized armature, wire 39,contact of neutral armature, wire 41, lamp g, wire 37 to source 28. Itwill be seen that this circuit is closed only when the relay isenergized in such direction as to close the contact 38 of the polarizedarmature. The circuits for the lamps 1" and g of signal C are similar tothese just explained for signal C. 46, 46, are sources of current whosemiddle points are connected with common wire 0 and whose terminals areconnected respectively with wires 47 and 50. Operatively connected witheach end signal S and S is a circuit controller 45 adapted to connectone wire or the other wire 47 with a wire 57 according as the sig nalindicates proceed or stop The circuit for relay E is from one terminalor the other of the source 46 at the east end of the stretch, throughwire 47 or 50, circuit controller 45, wire 57, armature contact 12 oftrack relay R, wire 48, relay E, wires 49, 37 and O to source 46. Itwill be seen that relay E is energized in one direction or the otheraccording as signal S indicates proceed or stop; when the signal Sindicates proceed, as shown in the drawing, relay E is energized in suchdirection that its polarized contact 35 is closed and contact 38 isopen, hence, the red lamp 1' of signal C is illuminated and green lamp 9is extinguished. In the form of control here shown, signal S iscontrolled by a neutral armature contact of relay E. The circuit forsignal S is from source 28 through wire 51, contact 52 of neutralarmature of relay E, wire 53, contact 54 of track relay R, wire 55,signal S, wires 56 and O to source 28. Hence, it is seen that signal Sis controlled both by signal relay E and by track relay R. The controlof signals S and C is similar to the control of signals S and C justexplained. It will be noted that when the stretch A is free from cars ortrains, end signals S and S indicate proceed and intermediate signals Cand C each indicate stop.

The operation of the system shown in Fig. 4 is as follows: Assume that acar or train passes through the stretch A from west to east. As this caror train enters the stretch A it opens track relay R, thereby causingsignal S to change to stop indication. The opening of relay R also opensthe circuit of relay E so that this relay opens. The opening of relay Eopens the circuit for signal S thereby causing this signal to change tostop indication. This operation of signal S reverses circuit controller45, thereby reversing the current through relay E, so that the polarizedarmature of this relay is reversed. Contact 38 of relay E is then.closed and contact 35 is opened so that the red lamp r of signal C isextinguished and the green lamp 9 of this signal becomes illuminated.

It will be seen from the foregoing explanation that signals C, Gnormally indicate stop and that the change of indication of signal Cfrom stop to proceed when an eastbound car enters the stretch A, dependsupon the change of signal S from proceed to stop indication. Hence, asthe eastbound car or train proceeds into the stretch and finds thatsignal C indicates proceed, the driver of such car or train knows thatsignal S at the opposite end of the stretch indicates stop As theeastbound car or train asses beyond the middle of the stretch, it rstopens track relay R and later permits track relay R to close. Theopening of relay R opens the circuit of relay E, which latter relay thenopens. The opening of relay E causes the green lamp 9 of signal C to beextinguished and the red lamp 1" of this signal to be illuminated. Theopening of relay E also opens at contact 52 the circuit of signal S sothat this signal continues to indicate stop; and the opening of relay Ropens the circuit of signal S so that this signal also continues toindicate stop. The closing of relay R permits relay E to close but thishas no effect on the signals. When the car or train leaves the stretchA, the closing of relay R closes the circuit of signal S which thenchanges to proceed indication; it also closes the circuit of relay E,and this latter relay in closing closes the circuit of signal S, whichsignal then also changes to proceed indication. The movement of signalsS and S to proceed position reverses contacts 45, thereby momentarilydeenergizing' relays E and E so that the neutral contacts of theserelays open momentarily. Means must be provided for preventing thismomentary opening of the contacts from releasing signals S and S andpermitting the signals to return to stop position; and this may beprevented by means well known in the art-for example by providingthesignalswith slow-releasing holding devices which will not permit thesignals to return to stop position upon a momentary interruption of theoperating current. 7 I 7 Referring now to Fig. 5', the apparatusand'circuits here shown are similar to those shown in F g. 1, exceptthat in Fig. 5 the' stretch A is provided with two trackcircuits a and aelectrically separated by insulations 27. The two track circuits areifedwith alternating signaling current by two transformers T and T,respectively, located adjacent the junction of the track circuits. Theoperation of the apparatus shown in this view is exactly the same as ofthat shown in Fig. 1, except that in Fig. 5 when an eastbound car ortrain passes through the stretch, the track relay 3 is not opened untilthe car or train enters track! circuit a, and track relay It closes assoon as the car or train leaves track circuit a. r

The arrangement of track circuit shown in Figs. 1 to at, inclusive, thatis, a single track circuit for each stretch having a source of signalingcurrent adjacent the middle and a track relay adjacent each end, ispreferably employed when the stretch is of medium length. When thestretch is comparatively short, the arrangement of two track circuitsper stretch as shown in Fig. 5 must be employed, because, if a singlecenter-fed track circuit were employed, a car or train entering thestretch might open the relay at the, other end and thereby block its ownprogress by causing the intermediate signal, which it is approaching, toindicate stop. Also when a stretch is too long to permit of a singletrack circuit because of limitations or" track circuit apparatus, it isnecessary to employ at least two track circuits, as shown in Fig. 5. Incase the stretch is too long for only two track circuits, it may, ofcourse, be divided into a larger number of track circuits.

shown in Fig. 5 is the equivalent of that shown in Fig. 1. It is alsounderstood that arrangements of signal control shown in F igs. 2, 3 andt may equally well be employed with the track circuit arrangement shownin Fig. 5.

Although I have herein shown and described only five forms of railwaysignaling embodying my invention, it is understood 7 that variouschanges and modifications may be made therein within the scope of theappended claims without depart Having thus described my invention,

what I claim is:

1. In combination, a stretch of railway track, two relays one connectedwith the tra'ckrails adjacent each end of the stretch,

It is understood, however, that for track circuits of medlum length, thearrangement ing from the a source of signaling current, connected withthe rails adjacent the middle of the stretch,

two end signals one located adjacent each end of the stretch, twointermedlate signals located respectively in advance of the two ends ofthe stretch but in the rear of-the point at which a car or train passingthrough the stretch from the adjacent end causes the track relay at theopposite end of the stretch to open, a signal circuit for eachintermediate signal which signal'cin cuit is controlled by the trackrelay at the other end of'the stretch, a circuit controller operativelyconnected with each interme-' diate signal and arranged to be closed oropen according as the signal indicates pro- 7 ceedor stop, and a signalcircuit for each end signal which signal c1'rcu1t 1s controlled by thecircuit controller for the adjacent in-' through the stretch, the relayfirst opened.

remaining open until after the other relay has opened, means forenergizing said re-' lays, two end signals located respectively adjacentthe ends ofthe said stretch 'for governing the entrance of cars ortrains into'the stretch, twointermediate signals located re- 7spectively in advance of the end signals but in the rear of the point atwhich a car or train passing through the stretch from the said end openstherelay at the opposite end, a signal circuit for each intermediatesignal which circuit is controlled by the relay first 7 opened by a caror train entering the stretch from the other end, a circuit controlleroperatively connected to each intermediate sig nal and arranged to beclosed or open according as thesignal indicates proceed or stop, and asignal circuit for each end signal which circuit is controlled by thecircuit controller'for the adjacent intermediate signal and by therelayfirst opened'by a car or train entering the stretch from the adl jacent end.

3. In combination, a stretch of r'ailway track, two track relaysconnected with'the track rails adjacent the ends of the stretchrespectively and arranged to be opened successively by a car or trainpassing through the stretch, the relay first opened remaining open untilafter the other relay has opened, each of said relays being mechanicallyindependent of the other, means for energizing said relays,two' endsignals located respectively adjacent the ends of the stretch, and twointermediate signals located respectively in advance of the end signalsbut in the rear of the point at which. a-car or train passing throughthe stretch fromthe adjacent end causes the track relay at the op- Intestimony whereof I aflix my signature posite end to open, and means forcontrolin presence of tWo Witneses. ling each end signal by both trackrelays, HENRY W. GRIFFIN. and means for controlling each intermediateWitnesses:

5 signal by the track relay at the other end of ARTHUR HOFFMAN,

the stretch but not by the adjacent relay. ARTHUR G. HOWGILL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

